Pies: No night vision goggles needed

Evidence: 59 • authority: 72

Night vision is the ability to see in low-light conditions, either naturally with scotopic vision or through a night-vision device. Night vision requires both sufficient spectral range and sufficient intensity range. Humans have poor night vision compared to many animals such as cats, dogs, foxes and rabbits, in part because the human eye lacks a tapetum lucidum, tissue behind the retina that reflects light back through the retina thus increasing the light available to the photoreceptors.

Evidence: 53 • authority: 92

Horse vision through two lenses: Tinbergen's Four Questions and the Five Domains.. To improve human-horse interactions and reduce the risk of injury, it is essential to adopt an equi-centric perspective that prioritizes how horses perceive their environment. This review focuses on the equine visual system, both because it is the most studied of the horse's senses and because misunderstandings about how horses see can lead to unsafe or unsustainable handling. By applying two complementary frameworks, namely Tinbergen's Four Questions and the Five Domains model, we examine equine vision from both a biological and a welfare-oriented perspective. We explore the anatomical and functional feature…

Evidence: 47 • authority: 92

Comparative Evaluation of Smartphone-Based Fundus Imaging Systems in Dogs and Cats.. Objective To compare the feasibility, image quality, acquisition time, and evaluator preference of four smartphone-based fundus imaging (SBFI) systems in dogs and cats using a handheld fundus camera as a reference device. Animals studied Twenty client-owned animals, including 10 dogs and 10 cats. Procedures Fundus images were obtained from 40 eyes (20 mydriatic and 20 non-mydriatic) using four SBFI systems (iExaminer Panoptic, NUN WFE-02S, OQVet, and VistaView) and a handheld infrared fundus camera (Aurora). Image acquisition success and acquisition time were recorded for each device. Image quality was inde…

Evidence: 47 • authority: 92

Effects of Indirect Pupillary Light Reflex Stimulation With Colored Light on Corneal Specular Microscopy Performance in Dogs.. Objective To compare the effects of indirect pupillary light reflex (PLR) stimulation using differently colored lights on corneal specular microscopy performance in dogs and to determine the influence of pupil diameter. Animals studied 20 client-owned dogs (38 eyes) with healthy corneas. Procedures In this prospective study, one eye underwent specular microscopy while the contralateral eye was exposed to white, red, or blue light in a randomized order. The duration of the technique was measured from tracking onset to imaging completion. A 30-s time limit was imposed…

Evidence: 47 • authority: 72

Vision is an important sensory system for most species of fish. Fish eyes are similar to the eyes of terrestrial vertebrates like birds and mammals, but have a more spherical lens. Birds and mammals (including humans) normally adjust focus by changing the shape of their lens, but fish normally adjust focus by moving the lens closer to or further from the retina. Fish retinas generally have both rod cells and cone cells (for scotopic and photopic vision), and most species have colour vision. Some fish can see ultraviolet and some are sensitive to polarised light. Among jawless fishes, the lamprey has well-developed eyes, while the hagfish has only primitive eyespots. The ancestors of modern…

Evidence: 43 • authority: 72

The tapetum lucidum (Latin for 'bright tapestry, coverlet'; tə-PEE-təm LOO-sih-dəm; pl.: tapeta lucida) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light available to the photoreceptors (although slightly blurring the image). The tapetum lucidum contributes to the superior night vision of some animals. Many of these animals are nocturnal, especially carnivores, while others are deep-sea animals. Similar adaptations occur in some species of spiders. Haplorhine primates, including humans, are diurnal and lack a tapetum lucidum.

Evidence: 37 • authority: 72

Animal reflectors or animal mirrors are important to the survival of many kinds of animal, and, in some cases, have been mimicked by engineers developing photonic crystals. Examples are the scales of silvery fish, and the tapetum lucidum that causes the eyeshine of dogs and cats. All these reflectors work by interference of light in multilayer structures with dimensions less than a wavelength, so can be classed as photonic crystals. Other animal photonic crystals have evolved to reflect narrow spectra, producing animal coloration.

Evidence: 37 • authority: 72

The cat (Felis catus), also called domestic cat and house cat, is a small domesticated carnivorous mammal. It is a member of Felidae, the family of mammals in the order Carnivora also colloquially referred to as cats. An obligate carnivore requiring a predominantly meat-based diet, it has retractable claws adapted to killing small prey species such as mice and rats. It has a strong, flexible body, quick reflexes, and sharp teeth, and its night vision and sense of smell are well developed. It is a social species, but a solitary hunter and a crepuscular predator. Cat communication includes meowing, purring, trilling, hissing, growling, grunting, body language, and scent marking. It can hear s…

Evidence: 36 • authority: 92

Comparison of Corneal Endothelial Imaging Techniques by Specular Microscopy in Unsedated Healthy Dogs.. Objective To compare unsedated noncontact specular microscopy imaging techniques for the canine corneal endothelium and identify the most effective technique. Animals studied Nineteen eyes of 10 systemically healthy, staff-owned dogs with clinically normal corneas were studied. Procedure Six imaging groups were divided according to the different techniques used in all eyes: central focusing, with (CP) or without (CN) induction of an indirect pupillary light reflex (PLR); peripheral focusing with (PP) or without (PN) an indirect PLR; PP with application of a contact lens (CL); and gaze fix…

Evidence: 36 • authority: 92

The Visual Umwelt of primates and Hippocampal Representations of Space.. Evolution sculpts the brain's sensory adaptations. Because these adaptations differ markedly across species, it is challenging for humans to fully comprehend how other animals perceive the world. For a nocturnal mouse, the subjective sensory world-its Umwelt-is dominated by odors, sounds, and textures, with visual input playing a secondary role. In contrast, the Umwelt of a diurnal primate is primarily visual, composed of colors, shapes, and hues, with less emphasis on olfaction, audition, or tactile cues. In mice and rats, hippocampal place cells are activated when the animal occupies specific locations in allocentric…

Evidence: — • authority: 38